SARS-CoV-2 proteins monitored by long-range surface plasmon field-enhanced Raman scattering with hybrid bowtie nanoaperture arrays and nanocavities.

The identification of biomacromolecules by using surface-enhanced Raman scattering (SERS) remains a challenge because of the near-field effect of traditional substrates. Long-range surface plasmon resonance (LRSPR) is a special type of surface optical phenomenon that provides higher electromagnetic field enhancement and longer penetration depth than conventional surface plasmon resonance. To break the limit of SERS detection distance and obtain a SERS substrate with increased enhancement ability, a bowtie nanoaperture array was sandwiched between two symmetric dielectric environments. Then, an Au mirror was inserted to form a metal-insulator-metal configuration. Finite-difference time-domain simulations revealed that numerous hybrid modes can be provided by this novel configuration (denoted as long-range SERS [LR-SERS] substrate). In particular, the LRSPR mode can be excited and reach the maximum value through the regulation of the polarizations of the incident light and the geometrical parameters of the LR-SERS substrate. The optimized LR-SERS substrate was then applied to detect SARS-CoV-2 spike (S) and nucleocapsid (N) proteins. This substrate displayed ultralow detection limits of ∼9.2 and ∼11.3 pg mL-1 for the S and N proteins, respectively. Moreover, with the help of principal component analysis and receiver operating characteristic methods, our fabricated sensors exhibited excellent selectivity and hold great potential for the diagnosis of SARS-CoV-2 proteins in real samples.

Radiological findings and clinical characteristics of pregnant women with COVID-19 pneumonia.

OBJECTIVE: To study chest CT images and clinical characteristics of COVID-19 pneumonia in pregnant patients to examine any correlation. METHODS: Between December 31, 2019 and March 7, 2020, 23 hospitalized pregnant patients with confirmed COVID-19 were enrolled in the study. Clinical presentations were collected retrospectively from records, including laboratory testing, chest CT imaging, and symptoms. Descriptive analysis and correlation of patients' clinical and CT characteristics were performed. Laboratory results from time of first admission and CT absorption (defined as reduction in lesion area, decrease in density, and absorption of some solid components) were compared between symptomatic and asymptomatic patients. RESULTS: Fifteen (65.2%) patients were asymptomatic with patchy ground-glass opacity in a single lung lobe. Eight (34.8%) patients were symptomatic with multiple patchy ground-glass shadows, consolidation, and fibrous stripes. Differences in lymphocyte percentage and neutrophil granulocyte rate between first admission and CT absorption were significant (P<0.001). Median absorption time was shorter in the asymptomatic group compared with the symptomatic group (5 vs 10 days; P<0.001). Median hospitalization time between asymptomatic and symptomatic patients was 14 vs 25.5 days; P>0.001. Median absorption time and length of hospitalization for all patients was 6 days (IQR 5-8) and 17 days (IQR 13-25), respectively. CONCLUSION: Radiological findings and clinical characteristics in pregnant women with COVID-19 were similar to those of non-pregnant women with COVID-19. Median absorption time and length of hospitalization in asymptomatic patients were significantly shorter than in symptomatic patients. Lymphocyte percentage and neutrophil granulocyte rate may be used as laboratory indicators of CT absorption.

Characteristics of Acute Pulmonary Embolism in Patients With COVID-19 Associated Pneumonia From the City of Wuhan.

The aim of this study was to describe clinical, imaging, and laboratory features of acute pulmonary embolism (APE) in patients with COVID-19 associated pneumonia. Patients with COVID-19 associated pneumonia who underwent a computed tomography pulmonary artery (CTPA) scan for suspected APE were retrospectively studied. Laboratory data and CTPA images were collected. Imaging characteristics were analyzed descriptively. Laboratory data were analyzed and compared between patients with and without APE. A series of 25 COVID-19 patients who underwent CTPA between January 2020 and February 2020 were enrolled. The median D-dimer level founded in these 25 patients was 6.06 µg/mL (interquartile range [IQR] 1.90-14.31 µg/mL). Ten (40%) patients with APE had a significantly higher level of D-dimer (median, 11.07 µg/mL; IQR, 7.12-21.66 vs median, 2.44 µg/mL; IQR, 1.68-8.34, respectively, P = .003), compared with the 15 (60%) patients without APE. No significant differences in other laboratory data were found between patients with and without APE. Among the 10 patients with APE, 6 (60%) had a bilateral pulmonary embolism, while 4 had a unilateral embolism. The thrombus-prone sites were the right lower lobe (70%), the left upper lobe (60%), both upper lobe (40%) and the right middle lobe (20%). The thrombus was partially or completely absorbed after anticoagulant therapy in 3 patients who underwent a follow-up CTPA. Patients with COVID-19 associated pneumonia have a risk of developing APE during the disease. When the D-dimer level abnormally increases in patients with COVID-19 pneumonia, CTPA should be performed to detect and assess the severity of APE.